This invention relates to an apparatus for dyeing the skeletons of the fetuses of an experimental animal such as a mouse for the purpose of teratogenic studies of animals.
For the teratogenic studies, the skeletons of the fetuses of a small animal such as a mouse are investigated in medical and pharmaceutical fields. To this end, the fleshy moieties of animal fetuses are dissolved out, and the bony moieties thereof are then dyed for easy observation or photographing.
When the skeletons collapse during treatment, it is impossible to grasp the overall shape thereof. Thus, the skeletons should be treated, while they are kept in shape.
With the foregoing in mind, the present inventors have invented an apparatus in which a treating liquid is circulated through a treating tank containing the fetuses of an animal to treat them without giving vibration thereto (Japanese Utility Model Kokai-Laid-Open-Publication Nos. 56-37588 and 57-152188).
In such a skeleton-dyeing apparatus, however, it is required to achieve uniform circulation of the treating liquid throughout the interior region of the treating tank. However, in the conventional apparatus simply designed to pour a treating liquid into a treating tank from the side thereof, its circulation became so uneven that there were variations in dyeing of the skeletons.
When a caustic potash solution of strong alkalinity is used to dissolve the fleshy moieties of fetuses with the conventional skeleton-dyeing apparatus, that caustic potash solution cannot be discharged as such to an effluent path (sewerage) for disposal, due to its strong alkalinity.
Hitherto, a waste liquid part of strong alkalinity has been stored in a separate vessel by an operator in the course of automatic operation of the apparatus, while another harmless waste liquid part has been discharged directly to an effluent path. For that reason, a piping line connecting the dyeing apparatus with the effluent path have had to be led to a separate vessel midway therebetween for receiving the waste liquid of strong alkalinity therein, thus causing a drop of efficiency.